Antibiotic Inhibition of Protein Synthesis

Prostaglandin synthesis inhibited by formamidine pesticides.

In summary, a facile approach for synthesis of ZCIS/ZnS core/shell NCs is reported here that (i) the as-prepared primary ZCIS alloyed NCs display single PL peaks in the range of 590-815 nm and (ii) pronounced blue-shift does not happen throughout ZnS shell growth. These improvements are really expected and helpful for synthesis of ZCIS/ZnS NCs used for in vivo NIR fluorescence imaging. Particularly, a corresponding hypothesis is also put forward to explain this inhibitory blue-shift. It's proposed that the reduced blue-shift should be profited from the inhibited cation exchange derived from aforehand added Zn2+ ions and the following size increase arising from ions accumulation. Furthermore, the as-prepared ZCIS/ZnS QDs is successfully transferred into aqueous phase. After the approval of biocompatibility by cytotoxicity test, the obtained QDs are conjugated with cRGD peptides for tumor targeted imaging.

A facile strategy is reported here for synthesis of Zn-Cu-In-S/ZnS (ZCIS/ZnS) core/shell QDs to address the synthetic issues that the unexpected blue-shift of CuInS2-based nanocrystals. In this strategy, Zn2+ ions are intentionally employed for the synthesis of alloyed ZCIS core QDs before ZnS shell coating, which contributes to the reduced blue-shift in photoluminescence (PL) emission. The experimental results demonstrate this elaborate facile strategy is effective for the reduction of blue-shift during shell growth. Particularly, a hypothesis is proposed and proved for explanation of this effective strategy. Namely, both cation exchange inhibition and ions accumulation are involved during the synthesis of ZCIS/ZnS QDs. Furthermore, the obtained near infrared (NIR) ZCIS/ZnS QDs are transferred into aqueous phase by a polymer coating technique and coupled with cyclic Arg-Gly-Asp peptide (cRGD) peptides. After confirmation of biocompability by cytotoxicity test on normal 3T3 cells, these QDs are injected via tail vein into nude mice bearing U87 MG tumor. The result indicates that the signals detected in the tumor region are much more distinguishing injected with ZCIS/ZnS-cRGD QDs than that injected with ZCIS/ZnS QDs.

Inhibition of Mammalian Mitochondrial Protein Synthesis …

Hyaluronan (HA) is an extracellular matrix glycosaminoglycan (GAG) involved in cell motility, proliferation, tissue remodeling, development, differentiation, inflammation, tumor progression, and invasion and controls vessel thickening in cardiovascular diseases. Therefore, the control of HA synthesis could permit the fine-tuning of cell behavior, but the mechanisms that regulate HA synthesis are largely unknown. Recent studies suggest that the availability of the nucleotide-sugar precursors has a critical role. Because the formation of UDP-sugars is a highly energetically demanding process, we have analyzed whether the energy status of the cell could control GAG production. AMP-activated protein kinase (AMPK) is the main ATP/AMP sensor of mammalian cells, and we mimicked an energy stress by treating human aortic smooth muscle cells (AoSMCs) with the AMPK activators 5-aminoimidazole-4-carboxamide-1-β- D-ribofuranoside and metformin. Under these conditions, HA synthesis, but not that of the other GAGs, was greatly reduced. We confirmed the inhibitory effect of AMPK using a specific inhibitor and knock-out cell lines. We found that AMPK phosphorylated Thr-110 of human HAS2, which inhibits its enzymatic activity. In contrast, the other two HAS isoenzymes (HAS1 and HAS3) were not modified by the kinase. The reduction of HA decreased the ability of AoSMCs to proliferate, migrate, and recruit immune cells, thereby reducing the pro-atherosclerotic AoSMC phenotype. Interestingly, such effects were not recovered by treatment with exogenous HA, suggesting that AMPK can block the pro-atherosclerotic signals driven by HA by interaction with its receptors.

It is produced from dihydrofolic acid by dihydrofolate reductase

AB - Helicobacter pylori infection is associated with gastritis, peptic ulcer, and even gastric malignancy. H. pylori's antibiotic resistance is the major obstacle preventing its eradication. A series of 3,4,5- trimethoxybenzylbenzimidazole derivatives were synthesized and evaluated for their anti-H. pylori activity. The compound, 2-fluorophenyl-5-methyl-1-(3,4,5- trimethoxybenzyl)benzimidazole (FMTMB), was determined as the most potent in the inhibition of H. pylori growth and pathogenesis of host cells. An in vitro H. pylori infection model revealed that FMTMB inhibited H. pylori adhesion and invasion of gastric epithelial cells. Results from this study provide evidence that FMTMB is a potent therapeutic agent that exhibits both anti-H. pylori growth properties and anti-H. pylori-induced pathogenesis of cells.

This reaction is inhibited by methotrexate

N2 - Helicobacter pylori infection is associated with gastritis, peptic ulcer, and even gastric malignancy. H. pylori's antibiotic resistance is the major obstacle preventing its eradication. A series of 3,4,5- trimethoxybenzylbenzimidazole derivatives were synthesized and evaluated for their anti-H. pylori activity. The compound, 2-fluorophenyl-5-methyl-1-(3,4,5- trimethoxybenzyl)benzimidazole (FMTMB), was determined as the most potent in the inhibition of H. pylori growth and pathogenesis of host cells. An in vitro H. pylori infection model revealed that FMTMB inhibited H. pylori adhesion and invasion of gastric epithelial cells. Results from this study provide evidence that FMTMB is a potent therapeutic agent that exhibits both anti-H. pylori growth properties and anti-H. pylori-induced pathogenesis of cells.

Recent

Synthesis of Zn-Cu-In-S/ZnS Core/Shell Quantum Dots with Inhibited …

N2 - Leukotrienes (LTs) are produced by several biosynthetic enzymes including cytosolic phospholipase A 2 (cPLA 2), 5-lipoxygenase (5-LO), and 5-lipoxygenase activating protein (FLAP) in the perinuclear area. In the present study, we showed that pretreatment with methyl-β-cyclodextrin (MβCD), a cholesterol-depleting agent, dramatically reduced the synthesis of LTs in response to A23187 in mast cells. A23187-induced LT synthesis was inhibited by pretreatment with MβCD, and this effect was reversed when cholesterol was added. In an approach to identifying the MβCD-sensitive protein(s), we observed that FLAP co-localized with flotillin-1, a lipid raft marker protein, in the lipid raft-rich low-density region of sucrose gradients. In addition, electron microscopic analysis revealed that FLAP co-localized with flotillin-1. Together, these results suggest that FLAP is present in cholesterol-rich lipid raft-like domains and that its localization in these domains is critical for LT synthesis.

Amino acid synthesis - Wikipedia

N2 - The formamidine pesticides, chlordimeform and amitraz, were shown to have both antipyretic and anti-inflammatory activity when given intraperitoneally to rats at 5 to 80 mg per kg. They reduced yeast-induced fever in rats with potencies intermediate between those of indomethacin and aspirin, and antagonized the carageenin-induced swelling of the hind paw. In both these actions, chlordimeform was more potent than amitraz. Both formamidines also inhibited the synthesis of prostaglandin E2 from arachidonic acid by bovine seminal vesicle microsomes. At an arachidonic acid concentration of 0.4 μM, the I50 values for chlordimeform and amitraz were 34 and 880 μM respectively, compared to 0.4 μM and 790 μM for indomethacin and aspirin. These aspirin-like actions may provide a clue to some of the physiological effects of the formamidines, which represent a new and unsual group of prostaglandin synthetase inhibitors.

Reviews

“ Water-soluble analogues of the antitumor alkaloid camptothecin (1) were prepared in which aminoalkyl groups were introduced into ring A or B. Most of the analogues were prepared by oxidation of camptothecin to 10-hydroxycamptothecin (2) followed by a Mannich reaction to give N-substituted 9-(aminomethyl)-10-hydroxycamptothecins (4-12) or by subsequent modification of Mannich product 4 (13, 15, 17, 19, 21). Others were obtained by modification of the hydroxyl group of 2 (25, 26) or by total synthesis (35, 42, 43). These analogues, as well as some of their synthetic precursors, were evaluated for inhibition of topoisomerase I, cytotoxicity, and antitumor activity. Although there was not a quantitative correlation between these assays, compounds that inhibited topoisomerase I were also cytotoxic and demonstrated antitumor activity in vivo. Further evaluation of the most active water-soluble analogue led to the selection of 9-[(dimethylamino)methyl]-10-hydroxycamptothecin (4, SK&F 104864) for development as an antitumor agent. In addition to its water solubility, ease of synthesis from natural camptothecin, and high potency, 4 demonstrated broad-spectrum activity in preclinical tumor models and is currently undergoing Phase I clinical trials in cancer patients. ”